Various contact lenses such as hard contact lens, gas-permeable hard contact lens, soft contact lens and the like have been rapidly prevailing in recent years. These contact lenses are sterilized by a bacteriocidal method including boiling or immersion in an agent for contact lenses containing a bacteriocidal agent. Sterilization by boiling shows superior effect, but requires complicated steps and may cause degradation of the contact lens.
While a method using a bacteriocidal agent can be conducted rather easily, the bacteriocidal agent widely used conventionally, such as benzalkonium chloride, benzethonium chloride, p-hydroxybenzoate, chlorohexydine gluconate, cetylpyridinium chloride and the like, are known to be readily adsorbed particularly onto soft contact lenses, and once adsorbed, are hardly released but accumulated on the lenses. When, for example, a contact lens, to which such bacteriocidal agent has been adsorbed and accumulated thereon, is worn, the anterior ocular segment tissue is stimulated and may develop allergic reaction, inflammation, corneal erosion and the like.
Therefore, an agent for contact lenses capable of superior bacteriocidal performance has been awaited, which is associated with less adsorption of the bacteriocidal agent contained therein onto any contact lenses and quick release thereof even if adsorbed, thus being less accumulative, and which can be used safely for any contact lenses with easy operation.